Electric hot-plate or heating unit.



J. (I. PATTEN- ELECTRIC HOT PLATE 0R HEATING UNIT. nrmcmou FILED on. 4. 915.

1,238,807. Patented Sept. 4,1917.

TTITJIL- INVENTOR. WITNESSES diam es 6. Fallen B Y 514M UNITED STATES PATENT OFFICE.

JAMES o. PATTEN, or xoxou 6,..1iin1eNs, As'smnon T01 GLOBE s'rovn & RANGE comor nokonb,.m:omnn

'nnncimrc now-PLATE on nni'rzm- To all'whomitmay concern: 2- K Be itxknown ohait' ILJAMEBeG. ,PAT'IEN, a; citizen. of! the United States,. residing; at Kokomo, county of Howard, Statmof Indianayhave invented certa-im-newand useimprovements; in Electric .Hoh-Plates. on Heating .Units of w-hieh. .thefollowing-is a specificatiom i This invention relatesi tot impmvcments in' electric hot i plates, oraheatinge iunitse- 1 T-he obgiectszofv the inventiomarez; 4

First, to provide "Improved-means of confining- .and delivering theradiant heat developed by theresistancecdils-or heating meansitozthe vessel or cooking utensilpleo'ed thereom .Second; tonrovide improved| means for seeming intimatecontact of the= metallic top plate in such a unit with the flata bottom-oil akettle oncooking: utensih Phind, to. provide impa'ovedi means. of; re-. taini'ng. the-heat within such athot plateand compelling. itsdeliveryto the kettle or cooking utensil disposed above.

Fourtlu. to provide improved means of providing .forzthe avoidance oie disanrenge: menti'of. pants-due to the expansion of-' the meta'lotop plate.

Further-.- objects: and objects relating to details and: economies of construction and operatiomw-ill definitely appean tronrthe detailed description to follow; 1 Ii accomplish the objecteozfi my, invention byithe devices and means describedtin the following specifioation.-. The invention is clearly defined and! pointed out inthe claims. a V

A strucwre. constitutingsa prezfievred embodiment of my invention is illustrated in the-accompanying drawing forming a part of this specification, in. which:

Figure I? isa top plan view 0st in hot plate or unit embodying the featunesof my invention.

Fig. II is a transverse-detail: sectional elevation view taken 011'!!! line oorresponding:to lline. 2-2.0f Fig L.

Fig: 1111 s a detail -'n-verted plan. view of the hot; plate asill'ustrated'imFig; I.

In the drawing. similwr'reference ehmrac ters refer to similar parts throughout the several views, and-. the. sectional views are taken looking innthevdine'etion of the little am-owset the ends ofithe-seebion lines.

Considering the numbered parts of the t 's p eeliitation (if Lettersriztent;

drawing nxy iinpionedihot plate isiintended for. use. in o: top plate! or structure and: the.

same oom grises: 11- cup 3 shape bottom metallic piecenhwnthingwhith is; an asbestos lining 2 which sunrfiunds aporcelain erother non.- conductonmla te-lg mA. metallic top plate 4 lSvIgQYiClfid which is secured inrplace by b0 the jeans! above-; ,enumerawd; An outer gnoovefigfistormedlin the upper face. of the porcelain plate/3, having perferably pollShBdi i vellea. Within the bottoms of these aredisposedheeting coils. Coils 8 ei a. attheinterminalstto suitable binding posts 9 and 10. i

A-.second. coil 11 is disposed in grooves 12; 1:3 which is; looped back and forth in substantially parallel releti'onrazt the central portion of, the plate: in elongated loops: and provided with a. portion extending; substantially parallel Ito therouter peripheral'g'roove 7- at each. side; e

. he tertninai 15. isconnected to the hindingpostdl and the terminal 16 is connected to) bindingpost. 10;. It will thus be seen that the. central: pontion'ofi the heating coil is; made. up o, portions disposed: in substantially parallel. relation. The-outer coil is preferably of. greater, resistance. The coils are efieetively retained in. position in! the bottomi oi the grooves; and attaching. devices. may be provided where found. necessat-y), consisting'of little cotter pins .or other means; the coils. may be cementedin place; I

The top late' 4. has .a .comparativet broadrunper orated. peripheral flange which is; eastwith slots 18, 16 on. opposite sides thereofuand. toward the side of theelongatedgroove. in the. plate at the center. A series of. segmental slots 19,.20, 21, 22 extend. substantially around the plate exce t for. the connecting supports 23 opposite t e ends-of: thegroovesat the center andl the oonnectionsflt and 25 at each side in proximity to the open slots 18 .and symmetrically opposite therefrom. Thepart 23. extends well in' at 27: and the part 26. extends well in Mltl'lBeOPPOSi-tit side, forming a. sort ofend to'the-eentral grid.

Se cuts.- o fi metal are disposed: between the s ots' at 28,.29'towardl the outside, and at.30,. 31 just. within the same and 32, 33 34, 35, and 36 are in parallel relation at the v 'Patel ltedsc'pt. 4, 191. A'ppflenltiomflzlied comm, 1015. semi h 52,912..

5 disposed; through .epentunes 6 through =outer grooves and are connected center forming elongated slots correspond mg to the grooves in the insulator plate beneath. On the opposite sides of each of the slots as formed extend little guard fingers 37 which prevent any article, such as a spoon, a knife, or a fork, from being dropped down into ,contact with the resistance heating'coils and thus grounding the same.

The purpose of this arrangement has been explained and is also specifically described in the application of Louth and Jackson, Ser. No. 42,403, filed J uly28, 1915.

In this invention the slotting for the screws is avoided by disposing one of the same within the plate at 26 and'screws' at each side in the connecting segments30, 31, so that there are three points ofengage ment in portions of the'plate"so disposed that they are not subjected to the highest expansion. This permits the metallic late to remain evenly in place over the insu ator plate, and the peculiar slottings and the radial slots at 18, 18 permitthe'exp'ansion to occur without material disarrangement of the plate in its relation to theinsulator plate beneath. l

The general contour of theupper face of the plate 4 is concave, as indicated at 17, so that the fiat bottom of a kettle orvessel 4' laced thereon would contact at the "perip ery, thus effectively retaining any heat within by confining the same at these points. Most vessels having sheet metal bottoms are a little convcxed and this depression causes them to fit into close contact with the heated metal of the top plate. The central heating of the same has a still further tendency to convex the samedown \vardly and the concave formation ofthe plate thus insures the most effective contact of the sheet metal bottom of a kettle or cooking utensil, thereby enhancing the de livery of heat through the walls thereof to the contents of the same. This is of very considerable advantage, as it utilizes to the fullest extent the heat developed by the electric current in the resistance coils.

The plate 4 projecting like a peripheral flange enables this heat unit to be used in a top plate, something after the fashion of a stove lid in the opening of a stove top.

I have not shown the connections for delivering the current hereto. The concaved metal top plate can be effectively made use of in other relations and the other features would be quite effective with a flat top plate like that referred to in the application above mentioned. The whole structure, however, is highly effective in the specific form in which it appears. The sheet metal container 1 protects the same against injury. The insulation, both of asbestos and,

the porcelain plate, retain the heat de-:' veloped by the resistance coils and cause the sanie to be delivered upwardly. The particular form of top plate insures the effective delivery thereof.

'From what I have stated, it is clear tha the structure can be considerably modified without departing from my invention. I, however, believe that the specific structure possesses a high degree of" merit andI desire-to .cl-aim :thesame in its specific form as well as broad as indicated in the appended claims. a s Having thus described my invention, what I claim as new and desire to secure by Let ters Patent is:" a L. In an electric heat unit, the combina: tion of an insulator plate with suitable grooves in the upper face thereof, a heating coil means disposed in the said grooves, a

metallic top shield plate disposed over the insulator plate; slotted to expose the coils and concave at the center on its upper surface to conform to the convexity of any vessel thereon, an asbestos packing around the =said insulator plate, a --metal bottom shield around the-bottom of-said packing, a plurality of screws disposed through the said top plate and insulator means and bottom metal shield, coacting for the purpose specified. i

2. In ari'electric heat unit, the combination of 'an insulator plate with suitable "grooves in the upper face thereof, a heat ing coil means disposed in the said grooves, a metallic top -shield plate disposed over the insulator plate, slotted to expose the coils and concave at' the center on its upper surfaoeto conform to the convexity of any vessel placed thereon, an asbestos packing around the said insulator plate, a plurality of screws disposed through the said top plate and insulator means, coacting forthe purpose specified. 5111 an electric heat unit, the combination of aninsulator plate with suitable grooves in the upper face thereof, a heating coil means disposed inthe said grooves, a metallic top shield plate disposed over the insulator plate, slotted to expose the coils and concave at the center on its upper surface to conform to the convexity of any vessel placed thereon, a pluralit of screws disposed through the said top p ate and insulator means, coacting for the purpose specified.

4. In an electric heat unit, the combination of an insulator plate with suitable grooves in the upper face thereof, a heating coil means disposed in the said grooves, a metallic top shield plate disposed over the insulator plate, slotted to expose the coils, an asbestos packing around the said insulator plate, a metal bottom shield around the bottom-of said packing, a plurality- 0f screws disposed through the said top plate and insulator means and bottom metal shield, coacting for the purpose specified.

5. In an electric heat unit, the combination of an insulator plate with suitable grooves in the upper face thereof, a heating coil means disposed in the said grooves, a metallic top shield plate disposed over the insulator plate, slotted to expose the coils, an asbestos packing around the said insulator plate, a plurality of screws disposed through the said top plate and insulator means, coacting for the purpose specified.

6. In an electric heat unit, the combination of an insulator plate with suitable grooves in the upper face thereof, a heating coil means disposed in the said grooves, a metallic top shield plate disposed over the insulator plate, slotted to expose the coils, a plurality of screws disposed through the said top plate and insulator means, meeting for the purpose specified.

7 In an electric heat unit, the combination of an insulator plate with suitable grooves in the upper face thereof, a heating coil means disposed in the said grooves, a metallic top shield plate disposed over the insulator plate, slotted to expose the coils and concave at the center on its upper surface to conform to the convexity of any vessel thereon, coacting for the purpose specified.

8. In an electric heat unit, the combina- Ooplee of this patent may be obtained for tion of an insulator plate with suitable grooves in the upper face thereof, a heating coil means disposed in the said grooves, a metallic top shield plate disposed over the insulator plate and concave at the center on its upper surface to conform to the convexity of any vessel thereon, coacting for the purpose specified.

9. In an electric heat unit, the combination with suitable electric heating means and a top shield plate therefor concaved on its upper surface, of a fiat bottomed vessel contacting with the outer upper surface of said top plate.

10. In an electric heat unit, the combination of suitable electric heating means and a top shield plate therefor concaved on its upper surface with a peripheral flange the interior slotted into protecting bars, and the peripheral flange slotted radially to compensate for expansion, as specified.

11. The combination of a heater having a concave upper surface and a flat bottomed vessel supported on the outer upper part of said surface.

In witness whereof, I have hereunto set my hand and seal in the presence of two witnesses.

JAMES C.PATTEN. [L.s.]

\Vitnesses MABEL WILSON, Mo'rr M. Un'r.

five cents each, by addressing the "commissioner of Patents, Washington, D. 0." 

